1. Field of the Invention
The present invention relates to an image forming apparatus.
2. Description of the Related Art
As this type of image forming apparatus, an image forming apparatus has been known which collects the waste toner attached to the surface of the image carrier using a cleaning member, transports the waste toner to a waste toner bottle (waste container) which is removable from an image forming apparatus body, and stores the waste toner in the waste toner bottle. In this structure, when the waste toner bottle is full of a waste (hereinafter, referred to as a “waste toner”) including the waste toner, it is replaced with an empty waste toner bottle. In the replacement operation, in general, while the waste toner bottle is removed from the image forming apparatus body, in order to prevent the inside of the apparatus from being contaminated by the waste toner flowing out from a discharge hole of a waste toner transport path in an image forming apparatus body, it is necessary to stop an operation of transporting the waste toner from the waste toner transport path to the waste toner bottle. When an image forming operation is performed with the transport operation of the waste toner being stopped, the waste toner remains in a cleaning device, which makes it difficult to perform a normal image forming operation. In addition, the waste toner which remains in the waste toner transport path without being transported is agglutinated by the waste toner transported by the image forming operation. In this case, even after the transport operation is resumed, the agglutinated waste toner still remains in the waste toner transport path, which hinders the appropriate transport of the waste toner. For this reason, while the waste toner bottle is removed from the image forming apparatus body, in general, the image forming operation is inhibited. Therefore, the time for which the waste toner bottle is removed from the image forming apparatus body is the downtime of image formation.
Japanese Patent Application Laid-open No. 2005-242274 discloses an image forming apparatus capable of reducing the downtime. In the image forming apparatus, a buffer (temporary storage unit) capable of temporarily storing the waste toner is provided in the middle of the waste toner transport path. In the image forming apparatus, when the waste toner bottle is removed, the transport of the waste toner from the buffer to the waste toner bottle is stopped, but the operation of transporting the waste toner to the buffer is continuously performed. In this way, even when the waste toner bottle is removed from the image forming apparatus body, it is possible to continuously perform the image forming operation until the buffer is full, without causing the above-mentioned problem.
However, in the image forming apparatus disclosed in Japanese Patent Application Laid-open No. 2005-242274, the buffer includes a buffer waste toner full sensor that detects whether the buffer is full or nearly full and a buffer waste toner empty sensor that detects whether the buffer is empty. When the amount of waste toner equal to or more than a permissible amount is transported into the buffer, the waste toner in the buffer is agglutinated, which hinders the discharge of the waste toner from the buffer, or the waste toner overflows the buffer to contaminate the inside of the apparatus. Therefore, in the image forming apparatus disclosed in Japanese Patent Application Laid-open No. 2005-242274, the buffer waste toner full sensor is an indispensable component in order to prevent the amount of waste toner equal to or more than the permissible amount from being transported into the buffer. However, in the structure in which the buffer including the sensors is provided, a component cost or a manufacturing cost increases since the sensors are provided and the layout of the buffer is limited since the wiring of the sensors needs to be considered.
It is an object of the present invention to at least partially solve the problems in the conventional technology.